forked from Minki/linux
ac64a9caa5
If access to user space failed we need to reconstruct
stack pointer and restore all register.
This patch fixed problem introduces by:
"microblaze: Add loop unrolling for PAGE in copy_tofrom_user"
(sha1: ebe211254b)
Signed-off-by: Michal Simek <monstr@monstr.eu>
268 lines
5.2 KiB
ArmAsm
268 lines
5.2 KiB
ArmAsm
/*
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* Copyright (C) 2009 Michal Simek <monstr@monstr.eu>
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* Copyright (C) 2009 PetaLogix
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* Copyright (C) 2007 LynuxWorks, Inc.
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*/
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#include <linux/errno.h>
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#include <linux/linkage.h>
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#include <asm/page.h>
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/*
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* int __strncpy_user(char *to, char *from, int len);
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*
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* Returns:
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* -EFAULT for an exception
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* len if we hit the buffer limit
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* bytes copied
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*/
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.text
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.globl __strncpy_user;
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.type __strncpy_user, @function
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.align 4;
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__strncpy_user:
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/*
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* r5 - to
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* r6 - from
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* r7 - len
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* r3 - temp count
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* r4 - temp val
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*/
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beqid r7,3f
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addik r3,r7,0 /* temp_count = len */
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1:
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lbu r4,r6,r0
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sb r4,r5,r0
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addik r3,r3,-1
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beqi r3,2f /* break on len */
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addik r5,r5,1
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bneid r4,1b
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addik r6,r6,1 /* delay slot */
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addik r3,r3,1 /* undo "temp_count--" */
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2:
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rsubk r3,r3,r7 /* temp_count = len - temp_count */
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3:
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rtsd r15,8
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nop
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.size __strncpy_user, . - __strncpy_user
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.section .fixup, "ax"
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.align 2
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4:
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brid 3b
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addik r3,r0, -EFAULT
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.section __ex_table, "a"
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.word 1b,4b
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/*
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* int __strnlen_user(char __user *str, int maxlen);
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*
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* Returns:
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* 0 on error
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* maxlen + 1 if no NUL byte found within maxlen bytes
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* size of the string (including NUL byte)
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*/
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.text
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.globl __strnlen_user;
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.type __strnlen_user, @function
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.align 4;
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__strnlen_user:
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beqid r6,3f
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addik r3,r6,0
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1:
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lbu r4,r5,r0
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beqid r4,2f /* break on NUL */
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addik r3,r3,-1 /* delay slot */
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bneid r3,1b
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addik r5,r5,1 /* delay slot */
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addik r3,r3,-1 /* for break on len */
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2:
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rsubk r3,r3,r6
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3:
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rtsd r15,8
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nop
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.size __strnlen_user, . - __strnlen_user
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.section .fixup,"ax"
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4:
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brid 3b
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addk r3,r0,r0
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.section __ex_table,"a"
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.word 1b,4b
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/* Loop unrolling for __copy_tofrom_user */
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#define COPY(offset) \
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1: lwi r4 , r6, 0x0000 + offset; \
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2: lwi r19, r6, 0x0004 + offset; \
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3: lwi r20, r6, 0x0008 + offset; \
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4: lwi r21, r6, 0x000C + offset; \
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5: lwi r22, r6, 0x0010 + offset; \
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6: lwi r23, r6, 0x0014 + offset; \
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7: lwi r24, r6, 0x0018 + offset; \
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8: lwi r25, r6, 0x001C + offset; \
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9: swi r4 , r5, 0x0000 + offset; \
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10: swi r19, r5, 0x0004 + offset; \
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11: swi r20, r5, 0x0008 + offset; \
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12: swi r21, r5, 0x000C + offset; \
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13: swi r22, r5, 0x0010 + offset; \
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14: swi r23, r5, 0x0014 + offset; \
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15: swi r24, r5, 0x0018 + offset; \
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16: swi r25, r5, 0x001C + offset; \
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.section __ex_table,"a"; \
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.word 1b, 33f; \
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.word 2b, 33f; \
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.word 3b, 33f; \
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.word 4b, 33f; \
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.word 5b, 33f; \
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.word 6b, 33f; \
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.word 7b, 33f; \
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.word 8b, 33f; \
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.word 9b, 33f; \
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.word 10b, 33f; \
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.word 11b, 33f; \
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.word 12b, 33f; \
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.word 13b, 33f; \
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.word 14b, 33f; \
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.word 15b, 33f; \
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.word 16b, 33f; \
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.text
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#define COPY_80(offset) \
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COPY(0x00 + offset);\
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COPY(0x20 + offset);\
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COPY(0x40 + offset);\
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COPY(0x60 + offset);
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/*
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* int __copy_tofrom_user(char *to, char *from, int len)
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* Return:
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* 0 on success
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* number of not copied bytes on error
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*/
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.text
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.globl __copy_tofrom_user;
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.type __copy_tofrom_user, @function
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.align 4;
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__copy_tofrom_user:
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/*
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* r5 - to
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* r6 - from
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* r7, r3 - count
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* r4 - tempval
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*/
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beqid r7, 0f /* zero size is not likely */
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or r3, r5, r6 /* find if is any to/from unaligned */
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or r3, r3, r7 /* find if count is unaligned */
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andi r3, r3, 0x3 /* mask last 3 bits */
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bneid r3, bu1 /* if r3 is not zero then byte copying */
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or r3, r0, r0
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rsubi r3, r7, PAGE_SIZE /* detect PAGE_SIZE */
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beqid r3, page;
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or r3, r0, r0
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w1: lw r4, r6, r3 /* at least one 4 byte copy */
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w2: sw r4, r5, r3
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addik r7, r7, -4
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bneid r7, w1
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addik r3, r3, 4
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addik r3, r7, 0
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rtsd r15, 8
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nop
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.section __ex_table,"a"
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.word w1, 0f;
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.word w2, 0f;
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.text
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.align 4 /* Alignment is important to keep icache happy */
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page: /* Create room on stack and save registers for storign values */
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addik r1, r1, -40
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swi r5, r1, 0
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swi r6, r1, 4
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swi r7, r1, 8
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swi r19, r1, 12
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swi r20, r1, 16
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swi r21, r1, 20
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swi r22, r1, 24
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swi r23, r1, 28
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swi r24, r1, 32
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swi r25, r1, 36
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loop: /* r4, r19, r20, r21, r22, r23, r24, r25 are used for storing values */
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/* Loop unrolling to get performance boost */
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COPY_80(0x000);
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COPY_80(0x080);
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COPY_80(0x100);
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COPY_80(0x180);
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/* copy loop */
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addik r6, r6, 0x200
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addik r7, r7, -0x200
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bneid r7, loop
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addik r5, r5, 0x200
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/* Restore register content */
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lwi r5, r1, 0
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lwi r6, r1, 4
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lwi r7, r1, 8
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lwi r19, r1, 12
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lwi r20, r1, 16
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lwi r21, r1, 20
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lwi r22, r1, 24
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lwi r23, r1, 28
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lwi r24, r1, 32
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lwi r25, r1, 36
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addik r1, r1, 40
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/* return back */
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addik r3, r0, 0
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rtsd r15, 8
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nop
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/* Fault case - return temp count */
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33:
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addik r3, r7, 0
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/* Restore register content */
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lwi r5, r1, 0
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lwi r6, r1, 4
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lwi r7, r1, 8
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lwi r19, r1, 12
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lwi r20, r1, 16
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lwi r21, r1, 20
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lwi r22, r1, 24
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lwi r23, r1, 28
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lwi r24, r1, 32
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lwi r25, r1, 36
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addik r1, r1, 40
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/* return back */
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rtsd r15, 8
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nop
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.align 4 /* Alignment is important to keep icache happy */
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bu1: lbu r4,r6,r3
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bu2: sb r4,r5,r3
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addik r7,r7,-1
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bneid r7,bu1
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addik r3,r3,1 /* delay slot */
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0:
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addik r3,r7,0
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rtsd r15,8
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nop
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.size __copy_tofrom_user, . - __copy_tofrom_user
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.section __ex_table,"a"
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.word bu1, 0b;
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.word bu2, 0b;
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.text
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